Genotoxicity chromium

The key to hexavalent chromium s mutagenicity and possible carcinogenicity is the abiHty of this oxidation state to penetrate the cell membrane. The Cr(VI) Species promotes DNA strand breaks and initiates DNA—DNA and DNA-protein cross-links both in cell cultures and in vivo (105,112,128—130). The mechanism of this genotoxic interaction may be the intercellular reduction of Cr(VI) in close proximity to the nuclear membrane. When in vitro reductions of hexavalent chromium are performed by glutathione, the formation of Cr(V) and glutathione thiyl radicals are observed, and these are beHeved to be responsible for the formation of the DNA cross-links (112). 

Nieboer, E. and S.L. Shaw. 1988. Mutagenic and other genotoxic effects of chromium compounds. Pages 399 441 in J.O. Nriagu and E. Nieboer (eds.). Chromium in the Natural and Human Environments. John Wiley, NY. 

Uyeki, E.M. and A. Nishio. 1983. Antiproliferative and genotoxic effects of chromium on cultured mammalian cells. Jour. Toxicol. Environ. Health 11 227-235. 

Excerpt 4D is from Chemical Research in Toxicology. The authors investigate the genotoxicity of three different chromium (Iff) compounds (chromium chloride,... 

PI Many studies have shown that not only Cr but also CD cause damage inside the cells. In this work, three CD compounds were examined for their impact on genotoxicity and cell proliferation in vitro. Chromium chloride added to E. coli strains in the Pro-Tox (C) test system induced lacZ gene transcription from several stress promoters. (Adapted from Plaper et al., 2002)... 

Plaper, A. Jenko-Brinovec, S. Premzl, A. Kos, J. Raspor, P. Genotoxicity of Trivalent Chromium in Bacterial Cells. Possible Effects on DNA Topology. Chem. Res. Toxicol. 2002,15, 943-949. 

Chromium(VI) compounds have been consistently genotoxic, inducing a wide variety of effects including DNA damage, gene mutation, sister chromatid exchange, chromosomal aberrations, cell transformation, and dominant lethal mutations. ... 

Parameters of the O Flaherty PBPK Model 2-5 Genotoxicity of Chromium In Vivo 2-6 Genotoxicity of Chromium(VI) In Vitro 2-7 Genotoxicity of Chromium(III) In Vitro... 

Information regarding genotoxic effects in animals after inhalation exposure to chromium or its compounds is limited. Sprague-Dawley rats that inhaled chromium fumes generated from powders of chromium metal by a plasma flame thrower at 1.84 or 0.55 mg chromium(0)/m3 (5 hours/day,... 

No studies were located regarding genotoxic effects in humans after oral exposure to chromium or its compounds. 

Information regarding levels of chromium(III) compounds that result in death is available only for the oral route. Systemic effects of acute- and intermediate-duration inhalation exposure to chromium(III) are limited to the respiratory system. Information on systemic effects of chronic inhalation exposure to chromium(III) is limited to a study that used a mixture of chromium(VI) and chromium(III). Studies of intermediate- and chronic duration oral exposure to chromium(III) failed to find any systemic, neurological, developmental, reproductive, or carcinogenic effects. The immunological and genotoxic effects of chromium(III) in animals have not been tested by the oral route. Information regarding effects of dermal exposure of animals to chromium(III) is limited to a study of skin ulceration after acute exposure and dermal sensitization tests. 

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